Clutch and brake assembly



H. M. STUELAND CLUTCH AND BRAKE ASSEMBLY Filed Nov. 30, 1942 Au 1, 1945.. 1; !i I INVENTOR.

\ HAROLD MQSTUELAND B 1 4 ATTORNEYS Patented Aug 1 19 45 1 I UNITED STATES PATENT OFFICE CLUTCH AND BRAKE ASSEMBLY Harold M. Stueland, East Moline, 111., designer to 331ml & Company, Moline, 111., a corporation of Application November to, 1942, Serial No. 467,448

7 Claims. (01. 192-18) The present invention relates generally to tion, in which reference is had to the drawings clutch. and brake assemblies, ,with particular refappended thereto, in which erence to those usedin connection with hoisting Figure 1 is a side elevational view of a clutch mechanism such as, for example, shown and deand brake assembly constituting one embodiment scribed in U. S. Patent No. 2,298,199, granted to o of the present invention;

Court and Stueland, October 6, 1942, and is in Figure 2 is a sectional plan view taken along I the nature of an improvement over the clutch aline 2-2 in Figure 1; and mechanism shown in that patent. Figure 3 is a sectional view taken through the The principal object of the present invention adjusting means for adjusting the control lever to relates to the provision of a clutch and brake it) compensate for wear inthe parts. assembly for hoists or the like, and arranged so Referring now to the drawings, the clutch and that the brake is normally held in braking en-" brake assembly is indicated in its entirety by hoisting position, the load'ls immediately stopped 26 t e e d of t e shaftand b s a sh de to ,thegovision of a. clutch andbrake assem ly in which the brake is normally held engaged. by face of which P22 13 wltlra' fncmon producj" I Similarly, when the pressure is relieved from the "trol mechanism. which Provides f adjustment it will-be evident that the braking surfaces 22,

' clutch and brakev frictional surfaces and other ment. Conversely, by shifting the brake element invention will beapparent to those skilled in the disengaged. ,The brake element 9 is provided gagement-and is not released until after the reference numeral 5 and comprises generally a clutch members are engaged, and furthermore stationary supporting shaft 6, on which are rothe clutch members are not released until after 15 t t b y Supported a P 9 driving nd d e the'brake elements are engaged. In other words, clutch members I, 8, respectively, and a pair of it is an object of my invention to provide a engageable brake elements 9, 10, attached to the clutch and brake assembly, with control mechadriven element 8 a d 0 t Stationary Shaft 3,

nism which insures that whenever the operator esp c releases the controls, the brake is instantaneously 2 One d of he st tionary shaft 6 is reduced applied. Afurther object 'of my invention rein diameter as indicated at II and is S pp lates to the provision o f a clutch and brake in a racket I 2. The stationary brakeelement mechanism for ahoist, which ischaracterized in' H1 is in the form of a bell shap d member having that whenever the control lever is released from a hub I3 adapted to eceive the reduced po n in suspended position, without any tendency for H on t e A p o lock nu 15 e the hoist to slip and let the load drop slightly bethreaded on t e d f t shaft d draw the fore the brake is applied. A further feature of Shaft and huh I t htly against the bracket l2. m invention i th t. th brake is remased to The opposite end of the stationary shaft'B is lower the load by swinging the control lever from 3o adJustably mounted on a structural angle supthe neutral position in a direction Opposite t port 16, by means which will be described later that in 'whichthe lever is actuated to raise the in more detail- 1ad V V The bell shapedbrake element It is provided ,Still a further object'of this invention relates with outwardly flared flange or skirt portion 20, which serves as a brake drum, the outer sur a strong spring and is released by the pressure exfii g ifg ET. i f gi gg g erted by the operator in engaging the clutch firml attagch d i f d1 11 b b wlth themesult'that the clutch must 40 drum portion 0 bgme n i ifzzitable i i i lits 2 i or be fully engaged before the brake 1s released. by any other means which is suitable for this i pose. Thus, the outer surface 22 of the braking clutch members, the brake actuating pring mat i erial is frustoconical in shape and is adapted which is moppositlon to the clutch pressure to engaget he cooperative inner surface 23 ofan gages the brake before he, clutch m m e have axially extending flange on the brake element 9. disengaged, .The interior braking surface 23'is also frusto- Still another object of this invention relates conical in fo m and thus by shifting the'brake to the provlsien 9 mounting means for the 0011-? element 9 in a direction away from the bracket I2,

lt latter t compensate f r Wear i the so 23 will be wedged together in braking engageparts. v 9 axially relative to the drum 20, toward the sup- These and-other objects and advantages of my I porting bracket I2, the braking surfaces can be are after a considerationof the following descripwith a radiall extending supporting flange 25,

which is rigidly secured by bolts 26 to a radially extending flange 21 adjacent one end of the driven member 8.

The driven member 8 comprises a winding drum 30, which is substantially cylindrical and provides for winding a flexible cable or the like, such as is commonly used for hoists, winches, and other devices to which my invention may be applied. My invention is not limited to winding drums,-however, for the driven member may be in the form of a gear or other suitable power transmitting member. As indicated in Figure 2, the drum 3G is formed in two parts 3|, 32, divided along a radial plane, and secured together by suitable cap screws 33.

The interior of the drum3ll is hollowed out as at 34, to reduce the weight, and is provided with journal bearings 35, 36 at opposite ends of the drum 30, which are adapted to rotate on a sleeve 31, which closely embraces'but'is slidable on the stationary shaft 6.

The sleeve 31. is prevented from rotating about ance provides suflicient movement of the drum 30 and sleeve 31 axially toward the bracket i2 to disengage the braking surfaces 22, 23, to permit the drum to rotate.

The drum 30 is rotated by means of a clutch, indicated generally by reference numeral 55.

The end of the drum 30 is provided with a radially outwardly extending flange 56 having an' annular rim 51 formed in the end face thereof, to which is attached a plurality of circumferentially spaced radially extending teeth (adaptcircumferentially spaced teeth 63 adapted to enthe axis of the shaft 6 by means of a large-key ,38, disposed in a keyway 39 extending longitudinally within the end portion ll of the shaft 6. The end of the key 38 is received within an axially extending slot 40 in the end of the. sleeve 31, thus permitting the latter to be shifted axially along the shaft 6 but prevented from rotating thereabout. The key 38 also xtends through aligned slots 4|, 42 in the hu iii of the brake element l0 and the hub of the bracket l2, respectively. Thus, the key 38 prevents relative rotation between the shaft 6, the bracket i2, the brake element 10, and the sleeve 31.

Normally, the brake surfaces 22, 23 are maintained in braking engagement with each other by means of a strong helical spring 45, which encirclesthe hub l3 and theend ofthe sleeve 31, exerting a strong continuous force in compression between the inner end of the bell-shaped gage the outer serrated edges of a plurality of driving clutch plates 64, in a manner well-known to those skilled in the art. The hub 60 of the 1 driving member I is provided with a journal v axially along the sleeve 66 in order to engage the brake element In and a flange plate, which extends in a substantially radial plane about the sleeve 31, and is rigidly fixed thereto by any suitable means such as by welding. Three thrust bearing disks 41, 48, 49 encircle the sleeve 31 between the flange 46 and the end of the drum 3!! and serve to transmit the force of the spring 45 from the flange 46 to the drum 3!], thereby wedging the braking surfaces 22, 23 into firm braking engagement with each other. Thrust bearing washer 41 is prevented from rotating about the axis of the sleeve by means of one or more pins extending through the flange 46 and projecting into slots in the circumference of the washer 41. Likewise, bearing washer 49 is made to rotate about the axis of the sleeve 31? with the drum v3!! bymeans'of one or more pins 5! setin thefid of the drum 30 and projecting a into one Or more slots in the circumference of the washer 49, The center washer 48 is circular and can either rotate with washer 49 or stand stationary with washer 41. These particular details of this thrust bearing are not essential in this invention, for any other suitable thrust bearing can be used between the sleeve 31 and the drum 30. I

It will be noted that normally the spring 45 presses against the flange 4s urging the sleeve 31 and drum 30 axially outwardly'and limited only by the engagement of the braking surfaces 22, 23. In this position of the sleeve 31 it-will be noted that thereis a small clearance between the end of the sleeve 31 and the end of the hub is, as indicated at 52 in Figure 2. This clearclutch plates 64 with the driven clutch plate 59 and flange 56. The driving member receives power from a suitable drive chain (not shown), which drives a sprocket 68, which is preferably integrally formed with e driving member 1.

' Other means for driving the member 1 can of course be used within the scope of my invention.

A thrust washer 1U encircles the shaft 6 between the two sleeves 66 and 31 and is adapted to bear against the adjacent end of the drum 3i! when axial. pressure is applied thereto through sleeve 66 as will be {later described. For all practical considerations, the two sleeves 31 and 66 and washer 10 can be considered as one integral member, and are only made in two parts as shown, to facilitate manufacture and assembly. A slight clearance is provided between the end of the drum and thethrust collar 10 to insure that the drum 30 will rotate freely upon the sleeve 31, when the brake is'disengaged.

The clutch and brake assembly is controlled by means of a manual control lever 15, the lower end of which is bifurcated to provide a pair of laterally spaced legs 16, 11, which are .pivotally mounted on a pair of trunnion bolts 18, which are supported in coaxial relation in a pair of laterally spaced bracket plates 19 rigidly fixed gr the angle member it between the horizontals vertical flanges of .the latter.. Thus, the lever is pivotally'mounted to' swing about the axis of the bolts 18, generally in avertical plane passing through the axis of the supporting shaft (5, toward and away from the clutch.- Each of the legs 16, 11 is provided with a cam 80, fixed by any suitable means, such as by welding, to the inner edge of the leg adjacent the driving member 1, and spaced vertically above the axis of the lever pivots 18. The cams are disposed substantially in contact, with a thrust collar 85,

I and the thrust collar 85, thus providing an efflcient thrust bearing between the earns 80 on the lever 15 and the driving clutchmember 1. It is now evident that when the lever 15 is swung toward the clutch, the cams 80 engage the thrust collar 85 and force the driving clutch member 1 axially toward the clutch driven member 8 to engage the clutch. As axial pressure is applied to the driving member 1 through the lever 15, it

is transmitted through the clutch plates, the

' drum 30, the thrust bearing washers 41, 49 and brake element 9 out of engagementwith the brake drum surface 22. As mentioned before, the limit of movement in this direction is determined by the end of the sleeve 31 engaging the hub I3 of the brake member ID. Since the clearance 52 is only in the order of a sixteenth to an eighth of an inch, it will be evident that the brake releases almost simultaneously with the engagement of the clutch, .but nevertheless, the clutch must be in full engagement before the brake-is disengaged. Therefore, there is no point in the range of the lever 15 between neutral and clutch engaged position, in which the drum is free to rotate.- After the sleeve 31 engages the hub I3, any desired amount of pressure can be applied to the clutch without further compression of the spring 45.

When the lever 15 is swung in the opposite direction from its neutral position, away from the clutch mechanism, the brake is released without engaging the clutch and thereby releasing the winding drum 30 so that it is free to rotate about the axis of the shaft 6. This is accomplished by means of a second pair of cams 90, fixed to the-lower ends of the legs 16, 11 on the inner surfaces thereof, by any suitable means suchas by welding. The cams 90 are offset below the pivot axis of the bolts 18 and are also offset inwardly from the cam 80, sothat they are adapted to engage a plate 9I, which is' disposed in a transverse vertical plane and is apertured toreceive the end of the sleeve 66, the latter being rigidly welded or otherwise fixed to the plate 9|. Thus, by swinging the lever away from the clutch mechanism, the cams '90 engage the plate Ill and force the sleeve 66 inwardly, transmitting pressure through the collar 10, the sleeve 31, and the flange 46, to oppose the spring 45 and press the latter until the end of the sleeve 31 abuts the end of the hub l3. During this movement, the collar engages the end of the drum 30 and shifts the latter axially, thereby separating the braking surfaces 22, 23, as described above. Inasmuch as movement of the lever away from the clutch mechanism also moves the cams 80 away from the thrust collar 85, no pressure is applied to the driving member 1, and therefore no engagement of the clutch plates 59, 64, occurs. neutral position, pressure is relieved from *the spring 45, whereby the latter shifts the "drum 30 axially of the shaft 6 and reapplies the brake to hold the drum stationary.

The operation of this embodiment of my inlift the load, the drum is rotated in order towind cable thereon, by swinging'the lever toward the clutch mechanism, thereby applying pressure to the thrust collar 85 and shifting the driving member 1 axially into engagement with the driven member 8,'pressure being applied through When the lever 15 is returned to its 7 the clutch plates 59, 64, .and through the drum 30, the thrust bearing plates 41, 48,- 49, and the flange 46, in direct opposition to the pressure of the spring 45, thereby shiftingthe braking surfaces 22, 23'out of engagement. is thus rotated. until the lever 15 is returned to neutraLwhereupon the spring 45 applies pressure through the flange 46, the thrust bearing plates 41, 48, 49, and the bolts 26, to reengage the brake surfaces 22, 23. The weight of the load rotates the drum in the opposite direction when the brake is released without engaging the clutch, and this is accomplished by swinging the lever 15 away from the clutchmechanismand applying pressure in opposition to the spring, 45, through the cams 90, the plate 92, the sleeve 66, collar 10, sleeve 31, and flange 46. It will be noted that the spring 45 returns the lever 15 to neutral position from either the raising or lowering position of the latter, whenever thelever is released by the operator, thereby holding the load at any position when the lever is released.

It will be appreciated that any wear in any of the thrust bearings or friction surfaces will cause a slight shift of the driving and driven members axially relative to the shaft 6, and therefore relative to the earns 80 and90. For instance, wear in the brake surfaces 22, 23 tends to cause the vention, as applied to a hoist, isas follows. To

drum to shift slightly toward the lever15, whereas wear in the clutch plates would'tend to increase the clearancebetween the cams and the thrust collar 85. Therefore, it is desirable that an adjustment be provided for shifting the lever with its pivot mountings toward and away from the clutch mechanism. This is accomplished by the adjusting mechanism-best shown in Figure 3. The outer end of the stationary shaft 6 is reduced in diameter'as indicated at 95, which is slidably received within a bore 96 in a sleeve member 91. The outer end of the portion is still further reduced in diameter and threaded as indicated at 98, and this portion 98 is threaded into the outer end of the sleeve 91, which is tapped to cooperate therewith. The sleeve member 91 is inserted through an aperture in the vertical flange IOI of the angle iron bracket I6, and the inner end of the sleeve member 91 is provided with a radial flange I02, whch'bears against the inside of the flange IOI to limit outer movement of the sleeve 91 relative to the flange I0 I. The outer surface of the sleeve member 91 is threaded at I03 to receive a lock nut. I04, which can be tightened thereon against the outer surface of the flange I M on the support, while the outer end of the sleeve member 91 is provided with flat sides I05 adapted to re-' ceive a wrench for the purpose of threadingxthe sleeve member 91 along the threaded end 96 of the shaft 6. I

Thus, byapplying a wrench to the sides I05 of the sleeve member 91, after the lock nut I04 has been loosened, the sleeve member 91 can be adjusted axially along the threaded end 98 in either direction to adjust the position of the shoulder I02 relative to the'shaft 6. Since the opposite end of the shaft is held rigidly stati0nary by the bracket I2, whereasthe angle iron support I6 is mounted on the upper end of a long and comparatively flexible standard I06, the am gle .iron I6, together with the pivot mounting of the lever 15 can be adjusted slightly with respectto the shaft 6, and thereby adjustingfthe cams 80 and 90 relative to the thrust collar 85 andplate 9|. 1

I do not intend my invention to be limited to The drum the exact details shown and described in connection. with this embodiment, as various modifications within the scope of my'invention will be apparent to those skilledin. the art.

1. A clutch and brake assembly comprising'a pair of driving and driven. cooperative clutch members, a pair of cooperative brake elements, one of :said elements being connected with said driven member, a spring fornormally holding said elements in braking engagement, means for applying a :force against said driving clutch memher through said driven clutch. member to oppose said spring and disengage said brake elements, and means for selectively applying a force independent of said driving clutch member to appose .said spring and disengage said brake elements.

'2. A clutch and brake device as set forth in claim 1, characterized further in that said force applying means includes a lever having a mounting means providing for actuating movement in both directions from aneutral position, means connecting said lever with said driving member for applying force against the latter when said lever is actuated in one direction from said neutral position, and means connecting said lever with said driven member for applying, force against the latter when said lever is actuated in the opposite direction from said neutral position.

3. A clutch and brake device comprising, in combination, a pair of driving and driven coop-' erative clutch members supported by means providing for rotation about a common axis and rel ative. axial shifting movement to engage and disengage said members, a pair of brake elements disposed coaxially with said, clutch members, one of said elements being stationary and the other of said elements being fixed to said driven member to rotate therewith and shiftable therewith axially relative to said stationary element to engage and disengage said elements, means normally biasing said elements into engagement, means at one end of said assembly for shifting said driving clutch member into engagement with said: driven member and for exerting pressure therethrough to oppose said biasing means and disengage said brake elements, and means at said one end. of the assembly and extending coaxially through. said driving member for shifting said driven member to disengage said brake elements.

4. A. rotary clutch and brake assembly com' prising a supporting shaft, a pair of driving and driven cooperative clutch members supported by said shaft for rotation about the axis of the latter and shiftable axially relative to each other to engage and disengage. said members, a pair of cooperative 'brake elements supported on said shaft and shiftable axially relative to each other to engage and disengage said elements, one of said elements being attached to said driven clutch member, means for applying a force against said driven member in one direction axially of said shaft to engage said brake elements, means for applying a force in the opposite direction to engage said clutch members and to disengage said brake elements, and means for selectively applying" a force against" said driven member in opposition to said first mentioned force applying means to disengage said brake elements without,

engaging said clutch members comprising a sleeve member mounted on said shaft within said clutch members and connected with one of said brake elements. I

5. A rotary clutch and brake assembly comprising a stationary supporting shaft, sleeve means mounted thereon and shiftable axially relative thereto, a pairof driving and driven cooperative clutch members journaled on said sleeve means and shiftable axially relative to said shaft and to each other to engaged and disengaged positions, a pair of cooperative brake elements, one of said elements :being fixed to said shaft and the other being attached to said driven clutch member to rotate and shift axially therewith to engage and disengage said brake elements and having a connection with said sleeve to shift axially there- With, spring means for normally biasing said' brake elements into engagement to hold said driven member stationary, means for shifting said driving member axially into engagement with said driven member and to apply axial pressure in the same direction to shift the driven member to disengage said brake elements, and means for selectively shifting said sleeve axially to disengage said brake elements against the bias of said spring means.

6. A clutch and brake: device as set forth in claim 5, characterized further in that said shifting and force applying means includes a lever having a mounting means providing for actuating movement in both directions from a neutral position, means connecting said lever with said driving member for applying a force against the latter when said lever is shifted in one direction from said neutral position, and means connecting said lever with said sleeve for applying force against the latter when said lever is actuated in the opposite direction from said neutral position.

'7. In a clutch and brake assembly, a support, a stationary shaft mounted thereon, a driven clutch member rotatably mounted on said shaft, a stationary brake element rigidly attached to said shaft, a rotatable brake element connected with said driven member, a stationary helical spring encircling said shaft and anchored there'- on, a thrust bearing for transmitting force from said spring to said driven member to shift the latter axially to interengage said brake elements,

a driving clutch member rotatably mounted on said shaft and engageable with said driven member "by shifting in a direction opposed to the pres- 5. member, thus releasing pressure between said annular brake member, a helical compression spring encircling said shaft between said brake drum and said driven member and tending to force" the latter axially away from said drum and thus apply'said brake, and a driving clutch mem-' ber rotatably mounted on said shaft on the oppositeside of said driven member and shiftable axially toward the latter into driving engagement therewith.

9. In a clutch and brake assembly, a support, a stationary shaft mounted thereon, a driven clutch member rotatably mounted on said shaft,

face. on: the outer side thereof, va driving: clutch membenrctatably mountedwn said shaft and having a friction surface cooperative. with the first mentioned frictionsurface by relative movementof said members toward eachother, a brake 1 drum in the former? a bell shaped member disposed adjacent the opposite end of said winding prising a stationary-supporting shaft, sleeve means mounted "thereon and shiftable axially relative there'to, =a drivenolutch member rotatably mounted on said sleeve means and comprising, a winding'drum having a flanged portion at each end thereof, one of said flanged portions having a friction surface on the outer side thereof,"adriving clutch member rotatably mounted on said' sleeve means and having afriction surface cooperative with the first mentioned friction surface by relativemovement of said members to-- ward each othergabrake drum rigidly mounted on said-shaft adjacent the opposite-end of said winding drum, an-annularbrake element fixedto the other-of said flanged portions of the latter,

:said brake element an'ddrumhaving cooperative conicalbraking surfaces adapted to interengage when said Winding drum is shifted axially away fromsaid'brake' drum, a flange'fixed to said sleeve means adjacent said brake drum andadapted to bear against the end of said driven member, a helical compression spring'disposed 'to bear; against said brake drum at one end and'against said sleeve flange' andytending' to force said winding drum awa'y from said brake drum to engage said brake surfaces, flange means associated with said sleeve means at the opposite endof said winding drum and adapted to bear against the latter to shift the drum -toward said brake'drum to disengage said braking surfaces," and control means-adjacent said driving member for selectively shifting said "driving member or said sleeve means against-said winding in' opposition to said spring to release saidbraking surfaces.

11; A clutch and brake-assembly as set forth in claim -lfl," further characterized in that said control means comprises a-rlever having'a pivot mountingmeans providing for swinging movement in both directions from a neutral position, camming' meanslon said leveron'one side of said pivot. and engageable' with said driving member to shift the latter axially when the lever is swung in one direction, and'foamming means on aid lever on the opposite' side-of said pivot and 'eng'a'gea-ble with said sleeve-means to-shift the latteraxlally when the leveris swung in the op- Q ite direction.

#12. A clutch and'brake'assembly as setforth in claim '10, further characterized'in that said con- ;trol means comprises a lever v having a pivot mentin both directions from a neutral position,

camming means on saidleverj on one side of said pivot and engageable withsaid driving member to shift the latter axially when the lever is swung in one direction, camming mean on said lever on the opposite side of said pivot and engageable with said sleeve means to shift the latter axially when the lever is swung in the oppositedirection, and adjustable means for shifting. said pivot mounting means axially relative to said support to compensate for wear in the friction surfaces and other v parts.

13. A clutch and brakeassembly comprising a pair of coaxialldriving and driven cooperative clutch members, a pair of cooperative brake elements, one of said elements being connected with said driven member, a spring for urgingsaid elements into brakin engagement, a thrust bearing associated'with said driving member, a control lever movable in'one direction to transmit thrust through said thrust bearing to shift said driving clutch member into drivingengagement with said driven clutch member in opposition to said' springto disengage said brakeelements, and a control member extending coaxially through said driving'clutch member and connected to in relatively stationary position adjacent said annular elementand arranged to coact with the latter' to brake said driven member responsive to axial shiftingmovement of the latter in one direction relative to said stationary element, a spring adapted to urge said driven member in said direction to engage said brake elements, a rotatable driving member disposed adjacent said driven member and axially shiftable relative thereto, a pair of coactable clutch'surfaces on said driving and'driven members, respectively, and adapted to be engaged responsive to axial shifting movement of said driving member in the other direction in which an axial force transmitted through said clutch surfaces shifts said driven member todisengage-said brake elements in opposition to said spring, a control lever shiftable in both direct-ions from a" neutral position in which said driven member is held stationary by said brake elements, means connecting said lever with said driving member to shift the latter axially to engage said clutch surfaces when the lever is shifted in one direction, and means extending axially through said driving member and shiftable axially relative thereto for connecting said lever with said driven member and said spring' to oppose the latter and shift said driven member away from engagement with said driving member and shifted in the opposite direction.

15. The combination set forth in claim 14, in-' cluding the further-provision that said control lever is pivotally supported intermediate itsends for angular'm'ovement about an axis substantial- 1y perpendicular to the axis of rotation of said clutch members, said lever -being engageable with said driving member :at a point of conta'ct spaced on @onelside of said lever axis and *engageable with said axially extending connecting "means at a point of contact spaced ion the/opposite side of said lever-axis. v I

'16. The combination set forth in claim .14, lincluding the further provision that said control lever is p-ivotally supported intermediate its ends for angular movement about an axis substantially perpendicular to the axis of rotation "of said clutch members, said lever being positioned adjacent said driving member, a thrust :be'aring between the latter and said lever, said -lever.h'aving cam'ming means :fixed thereto spaced along said lever from "said lever axis and. adapted to bear 'upon' said thrust bearing to shift said driv with, a driving fmember ijournaled for rotation};

on said control member and alsoshiitableaxially relative thereto, -a pair of cooperative clutch sur-. faces disposed on said drivingand driven members, --respectively, and coac'table by shifting said driving member axially in one direction, aspring anchored to said support and adapted to ,urge said control :mem'berand said driven member axially in the -'opposite direction, a rotary brake element fixed tosaid driven membena-relati-vely stationary brake element mounted on said supsport and coactable with saidrotary brake element to hold "said driven member normallysta- I tionar-y,-said brake elements being urged into ongagementby said spring and thereby serving to limit axial movement -of said driven member-in said opposite direction but disengageable by force transmitted axially by said driving member through-said clutchgsurfaces, dndcon-trol means for selectively "applying an axial force .in

opposition'to said spring-either through said driving member'a nd clutch-surfaces or through said control member, to disengage said brake elements. H a

18.-A rotary clutch-and brake assembly comprising a central control member disposed coaxial with the axis of rotation of saidassembly, supporting lmeans therefor providing ionaxial Shifting movement of said member relative thereto, a driven clutch member supported on saidcontrol memberand shiftable axially therewith, a driving member :journaled -for rotation on saidcontrol member and also shiftable axially re1ative'thereto,-a pair of cooperative clutch surfaces disposed on said driving and driven members, respectively, and coactable byshifting "saiddriving member axially in one direction, a

areas-are to :limit 'a'xial movement ofisaid driven member in said o'pposite direction but :disengageable by force transmitted axially 'by said driving- .member through said v'clutch isurfaces, and .a control lever having pivotal mounting :means intermediate its ends adjacent the outer ends: of :said driving member and said control member and swingable iii one directionto en'gage' said driving member on "one side of said .pivotal mounting means to apply an axial force thereagainst in opposition to said spring, and swingable in the opposite direction to :enga-gethe end-of said control member on the-opposite side'of said Lpivotal mounting to "apply an :axial force th-ereagainst to oppose said spring and disengage said clutch elements independent :of said fdriving member.

19. A rotary clutch and :brake assemblybomprising a central control member disposed coaxial with the axis of rotation of said assembly, supporting means Etherefor providing ,for. axial shifting movement of said member relative thereto but preventing rotationof said control member, a driven clutchmember-Journaled on said control :member, means defininga pair of shoulders on said control "member on opposite sides of said driven :member between which the latter is freely rotatable aboutisaid-axis of revolution, a pair of brake-elementsfixedly mounted onsaid driven-member and saidsupport, respectively, and interengageable to brake said driven member by-axial movementof the latter in -one direction, a spring anchored on said support and biased against saidcontrol member urging the latter axially in :said :one direction and transmitting force through ionebf said shoulders to engage said brake elements, a driving member journaled on said control member and shiftable axially relative thereto, apair of cooperative clutch surfaceson-said' driving and driven clutch members, respectively, said surfaces being engageable'in driving-relation by shifting saiddriving clutch member against said driven clutch member in the other direction in opposition to said spring, said brake elements being disenvgagealile byipressureexerted through said clutch surfaces, said driven member, and one of said shoulders, or through \said control member directly, and control means at one end of said assembly adapted to apply -an axial -force in opposition to said spring, either through :said driving member or through said central control member, selectively, for controlling said driven member in *opposite directions, respectively.

'20. A rotary clutch and brake assembly com- ,prisingastationary shaft, arigid support therefor, a control member slidably mounted in coaxial relation onsaid shaft and axially shiftable thereon, means preventing rotation of said control-member un -said shaft,-a. drivenclutch member :iournaled on said control ,membeiwmeans defininga pair of shoulders -on-said controlmember on opposite sides of said driven member between which the latter wisfreely rotatable, a pair of brake elements-fixedly mountedon said driven spring anchored tosaid support-and adapted to 'urgesaid control member and saiddriven mem ber axially in the opposite direction, a rotary brake element fixed tosaid driven member, a relatively stationary brake element mounted on saidsupportand=coactablewith said rotary brake element to hold said driven member-normally stationary, said brake elements being ;=urg-ed into engagement by, said spring and therebyserving ,75-

member and :said shaft, respectively, .and interengageable to brake said driven member by axial movement of f the latter in onedirection, a helical compressionspringenciroling saidlshaft :and tanchored to the latter said spring being disposed to bear against said control memberlurging the latter axially along said shaft insaidmne direction and transmitting foroe through ione of said shoulders toengagesaid-brake elements, a driving "member vjournaled on said control member and shiftable axially relative thereto, a pair of cooperative clutch surfaces on said driving 'and driven clutch members, respectively, said surfaces being engageable in driving relation by shifting said driving clutch member against said driven member in op'position to said spring, said brake elements being disen ageable by pressure exerted through said clutch surfaces, said driven member, and one of said shoulders, or through said control member directly, and a control lever near the adjacent outer ends of said driving 10 member and said control member and pivotally mounted on said support for swinging movement about an axis intermediate the ends of said lever, and means on said lever spaced on opposite sides of said axis and adapted to bear on said driving 

